# math_utils.py

def add(a, b):
    return a + b

def subtract(a, b):
    return a - b

def multiply(a, b):
    return a * b

def divide(a, b):
    if b == 0:
        raise ValueError("除数不能为0")
    return a / b

# 测试
import math_utils

print(math_utils.add(5, 3))
print(math_utils.subtract(5, 3))
print(math_utils.multiply(5, 3))
print(math_utils.divide(5, 3))